The proliferation of pathogens such as Staphylococcus aureus, Streptococcus pyogenes or Propionibacterium acnes, or of certain yeasts, can lead to dysregulation of the cutaneous system, or even more serious disorders of skin or of mucous membranes, such as eczema, candidiases, dermatitises, etc.
Many means of treatment against these pathogenic agents are known. The most conventionally used are antibiotics or chemical antibacterial agents. They are, for example, compositions based on aldehydes and derivatives.
Thus, the published patent application FR 2740039 describes the use of a substance chosen from aldehydes and bifunctional compounds, preferably glutaraldehyde, for inhibiting the attachment of strains of pathogens such as Staphylococcus aureus to keratinocytes and corneocytes.
Thus, hexachlorophene and its derivatives are known as antibacterial substances and are more particularly used against Propionibacterium acnes. 
However, these treatments are in general expensive and harmful to both the health and the environment. Alternative, nontoxic treatments are now known which consist in using the antifungal, bactericidal or bacteriostatic properties of certain strains of microorganisms.
Thus, PCT application WO 97/366603 demonstrates the antifungal properties of a strain of Lactobacillus casei. 
Other bacterial agents, such as the Bacillus, can also be used on skin or mucous membranes. Specifically, in application WO 98/47374, strains of Bacillus coagulans, Bacillus subtilis, Bacillus laterosporus and Bacillus laevolacticus are used in compositions intended to prevent bacterial, viral or fungal infections of skin or of mucous membranes.
The invention proposes to find a novel bacterial agent capable of controlling and regulating the cutaneous ecosystem in order to improve upon the deficiencies of the prior art.